sherwood



and I do hereby declare that the following is a full,

tant @anni tfioe. v

N. B. SHERWOOD, O NEW YORK, N. Y., ASSIGNOR T0 HIMSELF AND W. I-I. WILLSON, OF SAME PLACE.

Letters Paten-t No. 83,734, dated November 3, 1868.

ITPROVEMENT IN PLANO-FORTE-TUNING KEYS.

The Schedule reiened to in these Letters"Patnt and making part of the s'ame.

To all whom it 'may concern.-

Be it known that I, N. B. Snnnwoon, o f the city, county, and State of New York, have invented a new and useful Improvement in Piano-Forte-Tuning Keys;

clear, and exact description of the same, reference being had to the accmpanying drawings, forming a part cf this specification, in which- Figure 1 represents a vertical section of a tuningkey, constructed according to my improvement;

l Figure 2, an end view of the same, as seen from above and VFigure 3, a transverse section, showing the lower part and the base.

Similar letters of reference representcorresponding parts in the several figures. Y

lThis improvement relates to tuning-keys, which are operated by worm-wheel and endless-screw attachment, whereby a more accurate adjustment of the tension of piano-forte strings is effected.

ItY consists, first, in a shifting-'or movable frame, whereby the endless screw 'may be swung out of gear, enabling the handle to be applied to .the key direct when a new string is to be inserted, or when it is desirable for the string to be tuned quickly for any other purpose.

It consists, secondly, in an adjustable base, fitted to turn upon the lower end of a stand in which the key works, capable of having the stand so adjusted and secured within it by a ratchet and pawl, or their equivalents, as to permit the endless screw to stand in any direction most convenient for manipulation.

In order that others may be better enabled to understand the construction and operation of my improvcment, I will proceed to describe it with reference to the drawings. Y

A is a stand, fitted to an adjustable base, B.

O is a key, iitted into the stand A, so as to turn therein, and furnished at its upper end with a wormwheel, D. v

F is a frame, attached to the side of the stand A, near its upper end, and containing the bearings of the endless screw e.

This name is hinged'to turn on a' pivot, m, which provides for throwing the screw e out of gear, as illustrated by those parts of iig. 2 represented in blue outline, when it is necessary to apply the handle to the key direct ,provision for which application is afforded by a square head on the key, projecting above the worm-wheel.

c is a pawl, pivoted 'to the lower part of the stand A, by means of a screw, d,- its lower point engaging with a crown-ratchet wheel, S, provided on the upper part of the base, B, into which the stand A is fitted to turn freely, and' securedby a set-screw, g,-which screws into a tapped hole in the base, and enters a groove in the'stand.

h isa projection, attached to the base, B, for the purpose of engaging between the neighboring tuningpins of the piano-forte, while the key is upon any one string-pin, thereby preventing the base from turning while the operation of tuning is going on. l

The pawl c may be replaced by a similar but inverted crown-ratchet, the teeth thereof fitting into or between the teeth of the lower wheel, thereby forming a rag-wheelclutch.

In operating or using this invention, the base should be placed over or upon the pin to be tuned, the head of said pin entering into the cavity made to receive it, in the lower end of the key C, the projection h, of the bse, resting between the other tuning-pins contiguous thereto, so as to engage with them, in such a manner as to prevent the base, B, from turning.

By raising the pawl c from the'ratchet S, the stand A is permitted to be turned, till the handle is brought into the most convenient direction, when the pawl may be dropped into the place to secure the stand.

By turning the handle, when on the endless screw, the key C is given a slow and regulated movement, by means of the endless screw aud worm-wheel, or ii' it is desirable to give the key a quick motion, as is necessary in putting Vin and partially tightening up a new string, the frame F may be unlocked, and the screw e swung -out of gear with the wheel D, and the with an adjustable base, substantially as shown and described.

N. B. SHERWOOD. Witnesses:

A. LE CLERC, E. P. TRACY. 

